Collision Avoidance:RTS-CTS exchange A AAP RTS(A) RTS(B) reservation collision RTS(A) CTS(A) CTS(A) DATA(A) defer time! ACK(A) ACK(A)】 6:Wireless and Mobile Networks 6-226: Wireless and Mobile Networks 6-22 Collision Avoidance: RTS-CTS exchange AP A B time DATA (A) reservation collision defer